A beacon channel is often used to provide critical information for recovering data transmitted in a traffic channel. For example, the beacon channel can contain timing, frequency, or phase information necessary for the receiver to synchronize with a received traffic channel. Once the beacon channel is received, the receiver can extract the information from the beacon channel and use the information to identify and decode the traffic channel.
When the beacon channel is used to transmit the necessary information for decoding the traffic channel, it is critical that the beacon channel be protected to ensure that an unintended recipient cannot gain access to the data in the traffic channel. Most current schemes employ some form of time division multiplexing (TDM) of the traffic and beacon channels. However, when TDM is used, the beacon channel can be relatively easy to detect. Therefore, it can be relatively easy for an unintended recipient to obtain the sensitive information in the beacon channel that is required to decode the traffic channel.